12th Standard Syllabus & Materials
12th Standard
TN 12th Tamil செல்வத்துள் எல்லாம் தலை - வாழ்வியல் இலக்கியம் - திருக்குறள் Sample Question Papers Study Material - QB365 Set A
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NEW12th Standard
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NEW12th Standard
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NEW12th Standard
TN 12th Tamil அருமை உடைய செயல் -இலக்கணம் -படைப்பாக்க உத்திகள் Sample Question Papers Study Material - QB365 Set A
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Published on: 24/08/2019
Complex Numbers
Download Tamil Nadu 12th Standard Maths question papers, model tests, one-mark questions, important questions, and public exam papers in PDF format. Free study materials and answer keys for TN State Board students.
Questions + Answers key
Take MCQ Maths Test1.
If x = cos θ + i sin θ, then xn + \(\frac { 1 }{ { x }^{ n } } \) is ______
2 cos nθ
2 i sin nθ
2n cosθ
2n i sinθ
2.
If a = cos α + i sin α, b = -cos β + i sin β then \(\left( ab-\frac { 1 }{ ab } \right) \) is _________
-2i sin(α - β)
2i sin(α - β)
2 cos(α - β)
-2 cos(α - β)
3.
If zn = \(cos\frac { n\pi }{ 3 } +isin\frac { n\pi }{ 3 } \), then z1, z2 ..... z6 is _________
1
-1
i
-i
4.
5.
If z = \(\frac { 1 }{ 1-cos\theta -isin\theta } \), the Re(z) = ___________
0
\(\frac{1}{2}\)
cot\(\frac { \theta }{ 2 } \)
\(\frac{1}{2}\) cot\(\frac { \theta }{ 2 } \)
6.
If z = 1-cos θ + i sin θ, then |z| = _____________
2 sin\(\frac { 1 }{ 3 } \)
2 cos\(\frac { \theta }{ 2 } \)
2|sin\(\frac { \theta }{ 2 } \)|
2|cos\(\frac { \theta }{ 2 } \)|
7.
If z = \(\frac { 1 }{ (2+3i)^{ 2 } } \) then |z| = ____________
\(\frac { 1 }{ 13 } \)
\(\frac { 1 }{ 5} \)
\(\frac { 1 }{ 12 } \)
none of these
8.
9.
10.
If a = cos θ + i sin θ, then \(\frac { 1+a }{ 1-a } \) = ___________
cot \(\frac { \theta }{ 2 } \)
cot θ
i cot \(\frac { \theta }{ 2 } \)
i tan\(\frac { \theta }{ 2 } \)
11.
If \(\sqrt { a+ib } \) = x + iy, then possible value of \(\sqrt { a-ib }\) is ___________
x2+y2
\(\sqrt { { x }^{ 2 }+{ y }^{ 2 } } \)
x+iy
x-iy
12.
The value of (1+i) (1+i2) (1+i3) (1+i4) is ____________
2
0
1
i
13.
If \(\omega =cis\cfrac { 2\pi }{ 3 } \), then the number of distinct roots of \(\left| \begin{matrix} z+1 & \omega & { \omega }^{ 2 } \\ \omega & z+{ \omega }^{ 2 } & 1 \\ { \omega }^{ 2 } & 1 & z+\omega \end{matrix} \right| \)=0
1
2
3
4
14.
If \(\omega \neq 1\) is a cubic root of unity and \(\left| \begin{matrix} 1 & 1 & 1 \\ 1 & { -\omega }^{ 2 }-1 & { \omega }^{ 2 } \\ 1 & { \omega }^{ 2 } & { \omega }^{ 7 } \end{matrix} \right| \) = 3k, then k is equal to
1
-1
\(\sqrt { 3i } \)
\(-\sqrt { 3i } \)
15.
If \(\alpha \) and \(\beta \) are the roots of x2+x+1 = 0, then \({ \alpha }^{ 2020 }+{ \beta }^{ 2020 }\) is
-2
-1
1
2
16.
If (1+i)(1+2i)(1+3i)...(1+ni) = x + iy, then \(2\cdot 5\cdot 10...\left( 1+{ n }^{ 2 } \right) \) is
1
i
x2+y2
1+n2
17.
The principal argument of \(\cfrac { 3 }{ -1+i } \) is
\(\cfrac { -5\pi }{ 6 } \)
\(\cfrac { -2\pi }{ 3 } \)
\(\cfrac { -3\pi }{ 4 } \)
\(\cfrac { -\pi }{ 2 } \)
18.
If z = x + iy is a complex number such that |z+2| = |z−2|, then the locus of z is
real axis
imaginary axis
ellipse
circle
19.
If z is a complex number such that \(z \in \mathbb{C} \backslash \mathbb{R}\) and \(z+\frac { 1 }{ z } \epsilon R\), then |z| is
0
1
2
3
20.
21.
If |z| = 1, then the value of \(\frac { 1+z }{ 1+\overline { z } }\) is
z
\(\bar { z } \)
\(\cfrac { 1 }{ z } \)
1
22.
If |z - 2 + i | ≤ 2, then the greatest value of |z| is
\(\sqrt { 3 } -2\)
\(\sqrt { 3 } +2\)
\(\sqrt { 5 } -2\)
\(\sqrt { 5 } +2\)
23.
If z is a non zero complex number, such that 2iz2 = \(\bar { z } \) then |z| is
\(\cfrac { 1 }{ 2 } \)
1
2
3
24.
The value of \(\sum_{n=1}^{13}\left(i^{n}+i^{n-1}\right)\) is
1+ i
i
1
0
25.
|2+2i|
26.
|z|
27.
z is imaginary
28.
z is real
29.
Im(z)
30.
Re(z)
1.
(a)
2 cos nθ
2.
(a)
-2i sin(α - β)
3.
(b)
-1
4.
(c)
5.
(b)
\(\frac{1}{2}\)
6.
(c)
2|sin\(\frac { \theta }{ 2 } \)|
7.
(a)
\(\frac { 1 }{ 13 } \)
8.
(c)
9.
(d)
10.
(c)
i cot \(\frac { \theta }{ 2 } \)
11.
(d)
x-iy
12.
(b)
0
13.
Comparing the two given lines with
\(\vec { r } =\vec { a } +t\vec { b } ,\vec { r } =\vec { c } +s\vec { d } \)
we have, \(\vec { a } =-\hat { -1 } -3\hat { j } -5\hat { k } ,\vec { b } =3\hat { i } +5\hat { j } +7\hat { k } ,\vec { c } =2\hat { i } +4\hat { j } +6\hat { k } \) and \(\vec { d } =\hat { i } +4\hat { j } +7\hat { k } \)
We know that the two given lines are coplar, if \((\vec { c } -\vec { a } ).(\vec { b } \times \vec { d } )\)=0
Here, \(\vec { b } \times \vec { d } \left| \begin{matrix} \hat { i } & \hat { j } & \hat { k } \\ 3 & 5 & 7 \\ 1 & 4 & 7 \end{matrix} \right| =7\hat { i } -14\hat { j } +7\hat { k } \) and \(\vec { c } -\vec { a } =3\hat { i } +7\hat { j } +11\hat { k } \)
Then, \((\vec { c } -\vec { a } ).(\vec { b } \times \vec { d } )=(3\hat { i } +7\hat { j } +11\hat { k } )(7\hat { i } -14\hat { j } +7\hat { k } )\)
Therefore the two given lines are coplanar.Then we find the non parametric form of vector equation of the plane containing the two given coplanar lines. We know that the plane containing the two given coplanar lines is
\((\vec { r } -\vec { a } ).(\vec { b } \times \vec { d } )\)=0
which implies that \((\vec { r } -(-\hat { i } -3\hat { j } -5\hat { k } )).(7\hat { i } -14\hat { j } +7\hat { k } )\)=0. Thus, the required non-parametric vector equation of the plane containing the two given coplanar lines is \(\vec { r } .(\hat { i } -2\hat { j } +\hat { k } )\)=0.
14.
(d)
\(-\sqrt { 3i } \)
15.
(b)
-1
16.
(c)
x2+y2
17.
(c)
\(\cfrac { -3\pi }{ 4 } \)
18.
(b)
imaginary axis
19.
(b)
1
20.
(b)
21.
(a)
z
22.
(d)
\(\sqrt { 5 } +2\)
23.
(a)
\(\cfrac { 1 }{ 2 } \)
24.
(a)
1+ i
25.
2\(\sqrt { 2 } \)
26.
|\(\bar { z } \)|
27.
z = -\(\bar { z } \)
28.
z =\(\bar { z } \)
29.
\(\frac { z-\bar { z } }{ 2 } \)
30.
\(\frac { z+\bar { z } }{ 2 } \)
12th Standard Syllabus & Materials
12th Standard
TN 12th Tamil அருமை உடைய செயல் - செய்யுள்-தேவாரம் Sample Question Papers Study Material - QB365 Set A
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TN 12th Tamil நாகரிகம், தொழில், வணிகம், ஆளுமை - உரைநடை உலகம் -திரைமொழி Sample Question Papers Study Material - QB365 Set A
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Computer Applications

Biology

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Computer Applications

Computer Science

Business Maths and Statistics

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Chemistry

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Computer Technology

History

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